What's the answer ii

An experiment applies heat to a substance and produces a gas that is a new and different substance. Choose the true statement.

sergejj [24]

Im a bit torn here, lets look at the definitions of physical and chemical changes:
physical change changes only the phase/state of a substance, but not what the substance is
chemical change is a chemical reaction where a new substance is formed and energy is given off or absorbed.
(it just started raining and it smells really nice out my window)

clearly, this cannot be just a physical reaction. i think i would be inclined to pick B. but C. could have merit as an answer too. sorry for the ambiguity x

7 0

4 years ago

If an object what is 30 kg of mass is moving at 10 m/s to the right how much kinetic energy does it have

ki77a [65]

Explanation:

m=30

v=10

K.E=1/2mv^2

=1/2×30×10^2

=1/2×30×100

=1500 joule

6 0

3 years ago

Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolat

ad-work [718]

Answer:

The correct answer is 0.00582 grams.

Explanation:

In order to solve the question, let us consider the vapor pressure of H2O, as hydrogen gas is collected over water, therefore, we have to consider the vapor pressure of water in the given case. Let us assume that the pressure is 760 torr or 1 atm.

It is known that the vapor pressure of water at 40 degree C is 53.365 torr (Based on the data).

Therefore, the pressure of H2 will be,

P = 760-55.365 = 704.635 torr or 704.635/760 = 0.9272 atm

The volume of the hydrogen gas collected in the tube is 80 ml or 0.08 L

Temperature in Kelvin will be 40+273 = 313 K

To calculate the moles of hydrogen (H2) gas, there is a need to use the ideal gas equation, that is, PV= nRT, in this R is the gas constant, whose value is 0.0821 L atm/molK, and n is the moles of the gas.

By inserting the values in the equation we get:

PV = nRT

n = PV/RT = 0.9272 *0.08 / 0.0821 * 313

n = 0.00289 moles

The mass of H2 will be moles * molar mass = 0.00289 * 2.016

= 0.00582 grams.

7 0

3 years ago

I need help with these questions, please!

lbvjy [14]

Answer:

1. Ionic bond

2. High melting point and high boiling point for ionic bonds while covalent bonds have low melting and boiling point.

3. The similarity is that ionic and covalent bonding lead to the creation of stable molecules.

4. 4Fe + 3O2 → 2Fe2O3

5. It uses the process of fission.

6. Fission involves the splitting of radioactive elements into smaller particles/compounds while Fusion involves combining of two or more atomic nuclei to form one or more different atomic nuclei and subatomic particles.

7. Nuclear power plants produce little to no greenhouse gas.

Nuclear power plants produce a large amount of energy for a small mass of fuel.

Nuclear is less expensive.

6 0

4 years ago

How many moles are present in

olasank [31]

Answer: (a) There are 0.428 moles present in 12 g of $N_{2}$ molecule.

(b) There are 2 moles present in $12.044 \times 10^{23}$ particles of oxygen.

Explanation:

(a). The mass of nitrogen molecule is given as 12 g.

As the molar mass of $N_{2}$ is 28 g/mol so its number of moles are calculated as follows.

$No. of moles = \frac{mass}{molar mass}\\= \frac{12 g}{28 g/mol}\\= 0.428 mol$

So, there are 0.428 moles present in 12 g of $N_{2}$ molecule.

(b). According to the mole concept, 1 mole of every substance contains $6.022 \times 10^{23}$ atoms.

Therefore, moles present in $12.044 \times 10^{23}$ particles are calculated as follows.

$Moles = \frac{12.044 \times 10^{23}}{6.022 \times 10^{23}}\\= 2 mol$

So, there are 2 moles present in $12.044 \times 10^{23}$ particles of oxygen.

4 0

3 years ago